April 3rd, 2003, 10:59 PM
SIM card unlocking & PAYG SIMs
There's a few shops round my way that unlock blocked SIM cards for mobile phones. Just wondering how it's done? Not sure if you have Pay As You Go phones in the States...If you have a SIM card that's say in a phone that's on a contact phone you wouldn't be able to use it on a PAYG phone. Just wondering if it's possible to change that so you can use that SIM on any phone..Or is that the same as unlocking the card??
April 24th, 2003, 11:00 PM
Its not the SIM they unblock, its your phone. Some phones are tied to certain networks, say for instance u bought a nokia 8310 on O2, it may only allow O2 simcards in the phone (PAYG or contract - it doesnt matter), but unlocking it allows u to put any simcard from any network into it:
Genie (now O2 combined)
The SIM cards do get blocked if u type ur pin in wrong 3 times and then u need your PUK (personal unblocking code) to access it and that is availble from your service provider.
Entering a PUK code in wrong 10 times permantly bars the SIM and renders it useless !!
April 25th, 2003, 02:46 AM
This is in addition to Chris Wuks post...
I have a i90c that uses the nextel network (with the direct connect, wireless web, etc.). My phone also uses a sim card. The sim card saves all of your preferences, phone book, web favorites, network information, etc. You can move it from phone to phone. So... if I wanted to upgrade my phone, I don't have to delete all of the settings in my old phone and enter it all in my new phone. Simply pull the sim card out and put it in my new phone. Keeps the direct connect settings, phone number, phone settings which will be applied if the features are available on the new phone, and phone book will all cary over.
Pretty good idea. I am pretty rough on cell phones and I can go through 2 or 3 a year.
I was getting tired of having to enter in 50+ numbers and settings everytime I upgraded or got a new one.
Here is some more info about sim cards. Here is another good one.
Since this is a security site... here are some links to sim security concerns...
There are several more out there...
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April 25th, 2003, 09:03 AM
They can lock your phone to a specifik network (like the ones mentioned) or they can lock you phone to a specifk sim card so that only that one works.
There are many, many unlocking sites on the net.
I unlocked my siemens m35 using a proggie found on the net and a data cable.
This phone (siemens m35) is btw vulnarable to a DoS attack by sending a specially crafted sms to it. (there are more siemens phones vulnarable).
In my country (the netherlands) the gvt has made unlocking a phone illegal. Due to the fact that the software is copyright and it is forbidden to reverse engineer it.
Some guy running an unlocking service got fiend for 5000 euros (approx 5000$).
Just thought you should now.